Files....are not signed by a key accepted by this server

[iaschick 0]

Whenever I click on any server to play the DayZ Mod, it gives me a connection, then a box that says "Files..(C:\Program Files)..are not signed by a key accepted by this server. To play on this server, remove listed files or install additional accepted keys." and then disconnects and doesn't allow me to enter any server.

 

Now I am very new to this game and am a tad bit confused on how to approach this.  If someone could help me I would greatly appreciate it, for I have no idea what this means.  Thanks

[plexico 386]

What servers are you trying? You must make sure you have the right mods for the right servers, there are different variants of the DayZ mod such as Epoch.